Grinding machine for safety-razor blades



March 27, 1928. A

' A. E. FRIEDRICH GRINDING MACHINE Foa SAFETY RAZOR BLADES Filed Deo. 12. 1921 i111. Il lll/f u v #1,. nnlmw. n l

vswin' Patented 27, UNITE-D STATES l I 1,663,907 PATENT oFFlcF..

.ALBERT E. FRIEDRICH, OF BEBLIN-FRIEDENAU, GERMANY..

GRINDING MACHINE FOB. SAFETY-RAZOR BLADES.

Application illed December" 12, 1921, Serial No. 521,877, and in Germany December 16, 1920.

The present invention relates -to a grinding machine for safety razor blades of the double-edged type, and the invention has for its object to provide a machine performlng the grinding operation with perfect umformity on all four sides of the blade. y

A further object of the invention is to secure the blade being lifted from the grinding rollers at the moment when ythe direction of rotation of the grinding rollers is reversed, any injury to the surface, of the grinding rollers being thereby avoided.

The present invention is illustrated on the drawing, Fig. 1 showing, in end-elevation, one construction of the invention,

Fig. 2 a longitudinal section of the device,

Fig. 3 the same viewed from the other end,

Fig. 4 a longitudinal section of a somewhat modified construction,

Fig. 5 a longitudinal section of a third.

construction. 4

The ap aratus is enclosedin a casin :of suitable s ape and size and constructe of any material suitable for the purpose.- In the casing there is provided a partition 2 anda cover 3 between which two grinding rollers 4 and 5 are .'ournalled, and a roller 12 adapted to hold t e blade and vits holder.

The grinding rollers as well as the holding roller 12 receive theirvmotion from a drive shaft 11 journalled i-n the said artition 2 and the end' wall 1, the said s aft being adapted to be turned in either direction by means of a crank 19. On the shaft 11 Ithere is loosely mounted a gear wheel 14 engaging another gear wheel 13 provided on the holding roller 12 and, besides, there is firmly attached another larger drive gear engaging the inion 8 on the shaft' 6 of the roller 4 as. we as the gear wheel 9 on the shaft 7 of the roller 5. Y

It is preferable to make the gear wheel 13 relatively small, as the time consumed in g the blade from one grindingl position into the other one will thereby be reduced. Y

vThe motion is transmitted to this wheel 14 byv meansof a. friction coupli. and, by the rovision of the coupling on the drlving s aft 11. any axial or radial forces acting on the y heretofore commonly used gfindng' machines, will be avoided. Here y the shafts willbecome veryeasy `in their bearingsinthewa11s2and3,andtheywillpre lade shaft, as in the- 10 and a dish siaped friction disc 16 firmly attached to the shaft 11 by means of a "nut 17 and a lock nut 18. The friction disc 16 is held pressed against the gear Wheel 14 by a certain pressure and,

conse uently, tends to turn the gear wheel and, t ereby,- the holding roller in the same direction as thegrindin rollers 4 and 5, and if no blade is inserted 1n the holding roller 12, all three parts will revolve, but when a blade is inserted, the friction of the disc 16 against the wheel 14 will cause one edge of the blade to be pressed against the top face of one of the rollers, and the other edge against the bottom face of the other roller, both of the rollers being free to rotate in consequence of the power' transmission from the ear wheel 10.

I the shaft 11 is rotated in the opposite direction the safety razor-blade will 1mme diately be turned out from the one grindin position, and swing over into the other grin mg position in otherwise known manner.

AS the friction between the dist 1c and the wheel 14 is always the same, whether the shaft 11 be turned in one or the other Adirection, it will be seen that the grinding prestime invone and t'en for some timein the other direction, or the han'dle 19 may be moved back and forth.

'Ihe couplingI 16 may be constructed in various manners. .For instance, as shown" on Fig. 4, the wheel 14'may be fastened to lthe friction disc 16, which then co-operates The shaft 11 ma be turned first for someA with t fixed dist 17 rovidtd on the shaft 1'1.

, On Fig. 5 a thi vconstruction is shown. Here the gear wheels 13 and 14 are omitted, 4andinstead thereof the blade shaft supports "a flat friction disc 13, which co-operates with the two friction discs 14;i and 14 pro l vided on the shaft 11 and, as shown on the drawing, engaging the periphery of the disc 13. v Opposite the portion of the disc 14:8l which co-operates with the disc 13a, there is pro-- vided'between the two discs 14 and 14J a projection 14 serving to secure the friction between the said two discs and the inter-- mechanism is mounted. In other words all' of the parts with the exception of the handle 19 are contained in the casing.

Having now described my invention, what I claim as new .and desire to secure by Letters Patent is.:

1; In a Sharpener for double edged razor blades, a-pair of grinding rollers, a pinion secured to each of said grinding rollers, a

blade-holding roller mounted between said grinding rollers, a drive shaft parallel to and spaced from said rollers, a drive gear fixed to said driveshaft and adapted to. engage said pinions, acrank on said drive shaft adapted to be turned in either direction to actuate said drive gear, a friction,disksecurehto said blade-holding roller,y and a pair offdisks mounted on said drive shaft for frictinally engaging both faces o said friction A 2. A` Sharpener -for razor blades, comprising a casing, a drive shaft mounted insaid casing, a crank on said drive shaft, a pair of grinding rollers mounted -in said casing, a blade-holding roller mounted betweenvsaid grinding rollers, a friction disk secured to said blade-holdin roller, a .drive gear fixed to said drive 'sha1 pinions securedto said grinding rollers and ada ted to mesh with said drive gear, a pair o discs mounted on said drive shaft and adapted tofrictionally engage both aces of said frictiondisc to thereby press the blade againstl the grinding -rollers while the drive shaft isy being rotated.

In testimony whereof I aix signature.

i ALBERTE FRIEDRICii, 

